Browsing by Author "Saukkonen, Antti"

In future the importance of crop production will increase worldwide as a result of continuous population growth and changing diet routines from rice to cereals. Also the possibility to use cereals as biofuel rawmaterial will increase the need for crop cultivation area all over the world. In Finland the number of farmers is decreas-ing and farms are getting bigger and bigger. Seedtimes have to be done with low-input in labour force and for this reason the automatization of different sectors of work would ease the workload. Utilization of automation e.g in sowing would increase the accuracy and easiness in determination of working depth. Aim of this study was to develop automatic depth control system, which was based on measuring the position of coulters and lift cylinder. The study is part of the Farmix –project, which concentrates on integrated automa-tion of tractor and implement. The study utilized a combination of tractor and implement that were already instrumented with a system fulfilling the ISO 11783 (ISOBUS) standard. To meet the aim of the study, it required setting up a field experiment, in which material was collected for the working depth model. For the field experiment the sensors of seed drill’s coulters and lift cylinder were cali-brated. Coulters had three sensors and the lift cylinder one. The final working depth automatic was tested in the autumn sowings. The sowing depth was confirmed by measuring shoots manually in the field both in spring and in autumn sowing. Manual measuring was done from 2 meters distance and from the position of the left share. Calibrating the sensors of the coulters worked well, because the calibrationcurves were parallel within all coulters and the sensor of lift cylinder. Based on the material from field experiments done in spring a new working depth formula was created. When the position of the lift cylinder changed from 0 to 50 mm, the work-ing depth was theoretically 15 – 60 mm. Manual measuring in the field suggested that seeding depth was 20 to 50 mm so a correction factor had to be calculated. Accomplished working depth automatic was tested in autumn sowings and target working depths were 20 – 50 mm.Working depth automatic worked well in 30 mm and 40 mm test drives. Standard deviation of theoreti-cal working depth in these foregoing test drives was 4 – 9 mm compared to a target working depth. Based on the measurements taken in the field working depth was an average 5 mm deeper in lower seeding (target 20 mm). Deeper seeding depth (target 50 mm) couldn’t be reached and field measurements suggested that real seeding depth was 40 mm. This failure was caused by deep furrow type coulters that weren’t able to seed any deeper, altough the lift cylinder was completely closed.